Method and apparatus for inverting rigid or flexible sheets

ABSTRACT

The direction of movement of blanks of rigid or flexible sheet material is reversed and the blanks are inverted by subjecting them to centrifugal force sufficient to overcome gravitational effects and maintain driving engagement between endless flexible belts and the blanks while they are driven by the belts along an arcuate path.

0 United States Patent 1151 3,666,078 Blorseth 1 May 30, 1972 METHOD ANDAPPARATUS FOR [56] References Cited INVERTING RIGID 0R FLEXIBLE UNITEDSTATES PATENTS SHEETS 3,285,392 11/1966 WO0d..... ....198/128 72inventor; Elwin J. morseth, Cincinnati, Ohio 1,226,730 5/1917 Weston..l98/l36 [73] Assignee: The Mead Corporation, Dayton, Ohio PrimaryExaminer-Edwarii A. Sroka [22] Filed Mar 5 1970 Attorney-Irvin V. Gleim,Edward M. Tritle and Francis M.

Crawford 211 App]. No.2 16,865

57 ABSTRACT 52 vs. C] ..19s/33 AD, 271 76 The direction of movement ofblanks of rigid or flexible Sheet 51 1111.01 ..B65g 47/24, B65h 29/12material is reversed and the blanks are inverted by subjecting [58]Field of Search 198/33 AD, 20, 129, 184; centrifuga' m gravimima'271/75-76, 65; 214/] R, l S

effects and maintain driving engagement between endless flexible beltsand the blanks while they are driven by the belts along an arcuate pathv8 Claims, 6 Drawing Figures Patented May 30, 1972 4 Sheets-Sheet 5;

R.H M MM ES- W O MM w %%m w w 1 am Patented May 30, 1972 3,666,078

4 Sheets-Sheet 3 INVENTOR. [AW /V J B/OASETH BY MW METHOD AND APPARATUSFOR INVERTING RIGID OR FLEXIBLE SHEETS BACKGROUND The present inventionrelates to material handling and, more particularly, to apparatus andmethod for inverting blanks of sheet material, either rigid or flexible,while the blanks are being fed from one manufacturing operation andprior to a subsequent operation.

Blanks of sheet. material frequently require a treatment, such asapplication of a coating material, to be applied to both sides thereof.l-Ieretofore, this has required duplication of the treatment-applyingapparatus as well as additional and complicated apparatus for invertingthe blanks or has required manual inversion thereof, all of whichinvolves considerable time, expense, and inefficient use of availablemanufacturing areas. Accordingly, it is a principal object of thepresent invention to provide improved means and method for obviatingsuch difficulties and disadvantages and which is inexpensive,mechanically simple, is automatic in operation, and eliminates the needfor duplication of treatment-application equipment.

SUMMARY These and other objects and advantages are achieved inaccordance with the present invention which enables both sides ofworkpieces or blanks of rigid or flexible material to be treated at asingle work station. After conveying the workpieces past the workstation and applying desired treatment to one side of the workpieces,they are inverted and re-conveyed past the same work station to applythe same treatment to the opposite side of the workpieces. Inversion isaccomplished by endless belts frictionally driving the workpiecesthrough an arcuate path and subjecting them to centrifugal forcesufficient to overcome gravitational effects and to maintain drivingengagement between the belts and the workpieces.

In accordance with the present invention the blanks B are driven bybelts 21 along an arcuate path and are thereby subjected to centrifugalforce. And if the belt speed is sufficient to produce centrifugal forcein amount to overcome the effect of gravity, no additional means isneeded to maintain engagement between the belts and the inverted orpartially inverted blanks regardless of their physical size or weight.For example, it can be shown that to invert blanks in a semicircular arc6 feet in diameter in accordance with the invention, the speed of belts21 theoretically should be at least about 600 feet per minute. However,operating experience has shown that unexpectedly the improved inverter10 will operate satisfactorily and invert rigid blanks up to five feetin length without requiring additional engagement-maintaining means atmaterially reduced belt speeds which produce centrifugal force amount.-ing to as little as two-thirds the effect of gravity.

DESCRIPTION FIG. 1 is a diagrammatic top plan view of conveyor apparatusincluding improved inverting apparatus embodying the present invention;

FIG. 2 is a diagrammatic side elevation view of the embodiment of FIG.1;

FIG. 3 is a side elevation view of the inverting apparatus of FIG. 1;

FIG. 4 is a view, looking in the direction of arrows 4-4 in FIG. 3, withthe belts removed;

FIG. 5 is a view, looking in the direction of arrows 5-5 in FIG. 3,showing how the belts are laced around the idler rolls; and

FIG. 6 is a view, looking in the direction of arrows 6-6 in FIG. 3,showing the belt guides.

Manufacturing operations often require treatment of both sides of panelsor blanks B of either rigid or flexible sheet material such apaperboard, fiberboard, wood, metal, and the like. After treatment ofone side, the panels of blanks need to be inverted to receive treatmentof the opposite side.

To facilitate an understanding of the construction and operation of thepresent invention and its relationship with other apparatus inconnection with which it may be used, there is shown diagrammatically inFIGS. 1 and 2 an improved inverter 10 together with conveyors l1, 12,I3, and arranged in operative relationship for subjecting both sides ofpanels or blanks B to a manufacturing operation, such as application ofa coating material, at a single work station 14.

The blanks are fed by conventional blank separating and feeding means 15to conveyor 11 which conveys the blanks to and from the work station orcoater 14 and delivers the coated blanks to the inverter 10. In additionto inverting the blanks, the inverter reverses the direction of theirmovement and also elevates the blanks which are then placed on anelevated conveyor 13. As the blanks are discharged from conveyor 13,they are straightened by a side guide 16 and their movement is arrestedby a stop 17 so that they fall onto another blank separating and feedingmeans 18. The then inverted blanks are fed by the separating and feedingmeans 18 onto conveyor 12 which, in turn, feeds the inverted blanks toand from the coater 14 following which they are removed to storage or toother manufacturing operations.

As shown in FIGS. 3 and 4', the inverter 10 essentially comprises aconveyor including spaced apart rollers 19 and 20 around which aplurality of endless flexible belts 21 are reeved. As described moreparticularly hereinafter, as belts 21 pass between rollers 19 and 20adjacent belts pass through different individual paths whichcollectively approximate an arcuate path between rollers 19 and 20 andtangent thereto at the path extremities.

Rollers l9 and 20 are rotatably supported in a fixed framework 22 whichalso rotatably supports idler roller 23, tension adjustment roller 24,and a plurality of rollers 25-35. As shown in FIG. 3, rollers 25-35 arespaced apart and their respective axes of rotation are positioned on acircular arc the center of which is midway between rollers 19 and 20.

Guide pins 36 depend from a member 37 which is supported by framework22, and maintain desired spacing between individual belts 21. Tensionadjustment roller 24 is rotatably supported at one end of a rock member38 which, in turn, is pivotally connected'to framework 22 to providetension adjustability for belts 21 which are reeved around rollers 19and 20, idler roller 23, tension adjustment roller, and certain ones ofrollers 25-35.

The various paths of the individual belts 21 is best shown in FIGS. 3and 5. After being reeved around roller 19, belt 21a is reeved underrollers 28 and 32 and then around roller 20, and does not contactrollers 25-27, 29-31, nor 33-35. Similarly, after leaving roller 19,belt 21b is reeved around rollers 27, 31, and 35 and does not engagerollers 25, 26, 28-30, and 32-34. Belt 210 is reeved around rollers 19,26, 30, 34, and then around roller 20 and does not engage the otherintervening rollers. Belt 21d is reeved around rollers 19, 25, 29, 33,and 20 and does not engage the other intervening rollers. This samereeving pattern is repeated with belts 21a, 21b, 21c, and 21d, and asimilar reeving pattern is employed with belts 21a", 21a', 21b",21b"',21c", 20", 21d, and 21d. All belts 21 are driven by roller 19 which, inturn, is driven by belt 39 and a pulley 40 connected to a motor 41.

In operation rigid or flexible blanks B are fed from a stack by blankseparating and feeding means 15 onto conveyor 11 which conveys theblanks past a workstation such as coater 14 which applies a coatingmaterial to the upper sides of the blanks. After passing theworkstation, the blanks move toward and are received by the inverter 10.

As a blank leaves conveyor 1 l and moves over roller 19, the forwardedge of the blank is frictionally engaged by one or more of the belts 21and driven upwardly through the arcuate path defined collectively bythese flexible belts as they pass through individually difi'ering pathswhile moving between rollers l9 and 20. Movement along such pathreverses the general direction of movement of the blanks and alsoinverts them so that their coated sides face downwardly and their uncoated sides face upwardly as they pass roller 20 and are received ontoconveyor 13. Operating experience has shown that the action of beltsunexpectedly tends to automatically straighten the blanks during theirmovement between rollers 19 and 20 even though they may be skewed tosome degree relative to the direction of their movement along conveyor11 at the time they are engaged by the inverter belts.

In accordance with the present invention, the blanks B are subjected tocentrifugal force during the inverting process since the belts 21 drivethe blanks along an arcuate path and reverse their direction ofmovement. Such centrifugal force acts in opposition to the effect ofgravity. Accordingly, the improved inverter 10 does not requireadditional means to maintain driving engagement between the belts andthe inverted or partially inverted blanks if the magnitude of such forceis equal to or exceeds the effect of gravity. Unexpectedly, operatingexperience has shown that rigid blanks having a length of about 5 feetare readily inverted while they are driven along an arcuate pathapproximating a semi-circular are 6 feet in diameter by an inverterembodying the present invention without any such additionalengagement-maintaining means even when the speed of belts 21 was reducedand the centrifugal force magnitude was as little as about two-thirds ofthe effect of gravity. Such inverter will handle flexible blanks havinga length greater than 5 feet if the blanks are subjected to sufficientcentrifugal force to overcome the gravitational effeet.

The inverted blanks are discharged from the inverter 10 onto overheadconveyor 13 which conveys the blanks to blank separating and feedingmeans 15. The inverted blanks are then fed onto conveyor 12 whichconveys them to work station 14 where a coating is applied to the thenuppermost sides of the blanks, and thereafter removes the coated blanksto storage or to another manufacturing operation.

While a particular embodiment of the invention has been illustrated anddescribed, it will be obvious to those skilled in the art that variouschanges and modifications can be made without departing from theinvention, and it is intended in the appended claims to cover all suchchanges and modifications that fall within the true spirit and scope ofthe invention.

What is claimed is:

1. Apparatus for inverting blanks of rigid or flexible materialcomprising first and second rotatable rolls a plurality of flexibleendless belts reeved around said rolleis, each of said belts having anexposed surface for frictionally engaging and driving said blanks whencontacted thereby and when said belts are driven,

drive means operatively connected to one of said rolls for driving saidbelts, and

guide means engaging said belts and directing adjacent individual beltsalong individually different arcuate-like paths between said rolls.

2. Apparatus according to claim 1 wherein said guide means comprises aplurality of idler rolls.

3. Apparatus according to claim 2 wherein individual belts are reevedaround certain individual idler rolls.

4. Apparatus according to claim 2 wherein the axes of said idler rollsare disposed along an arcuate path extending between said first andsecond rotable rolls.

5. Method of inverting and reversing direction of movement of blanks ofrigid or flexible material comprising the steps of moving the blanksonto a conveyor having a flexible endless belt,

driving the blanks along a semi-circular arcuate path defined by saidbelt by frictional engagement between said belt and the blanks, and

maintaining said driving engagement between said belt and the blanks bysubjecting the blanks to centrifugal force during their movement alongsaid path to overcome gravitational effects and to maintain saidfrictional engagement, wherein said semi-circular path has a diameterexceeding the dimension of a rigid blank in the direction of itsmovement. 6. Method according to claim 5 wherein said path rs asemicircular arc having a diameter exceeding the dimension of a rigidblank in the direction of its movement.

7. Method according to claim 5 wherein the magnitude of said centrifugalforce is at least about two-thirds of the weight of said blank.

8. Method according to claim 7 and additionally including the step ofdischarging said blank from said belt at an elevation above saidrectilinear path and in a direction generally opposite to that of saidinitial moving step.

1. Apparatus for inverting blanks of rigid or flexible materialcomprising first and second rotatable rolls a plurality of flexibleendless belts reeved around said rollers, each of said belts having anexposed surface for frictionally engaging and driving said blanks whencontacted thereby and when said belts are driven, drive meansoperatively connected to one of said rolls for driving said belts, andguide means engaging said belts and directing adjacent individual beltsalong individually different arcuate-like paths between said rolls. 2.Apparatus according to claim 1 wherein said guide means comPrises aplurality of idler rolls.
 3. Apparatus according to claim 2 whereinindividual belts are reeved around certain individual idler rolls. 4.Apparatus according to claim 2 wherein the axes of said idler rolls aredisposed along an arcuate path extending between said first and secondrotable rolls.
 5. Method of inverting and reversing direction ofmovement of blanks of rigid or flexible material comprising the steps ofmoving the blanks onto a conveyor having a flexible endless belt,driving the blanks along a semi-circular arcuate path defined by saidbelt by frictional engagement between said belt and the blanks, andmaintaining said driving engagement between said belt and the blanks bysubjecting the blanks to centrifugal force during their movement alongsaid path to overcome gravitational effects and to maintain saidfrictional engagement, wherein said semi-circular path has a diameterexceeding the dimension of a rigid blank in the direction of itsmovement.
 6. Method according to claim 5 wherein said path is asemi-circular arc having a diameter exceeding the dimension of a rigidblank in the direction of its movement.
 7. Method according to claim 5wherein the magnitude of said centrifugal force is at least abouttwo-thirds of the weight of said blank.
 8. Method according to claim 7and additionally including the step of discharging said blank from saidbelt at an elevation above said rectilinear path and in a directiongenerally opposite to that of said initial moving step.